The American legal system, as well as some other legal systems around the world, relies heavily on written judicial opinions, the written pronouncements of judges, to articulate or interpret the laws governing resolution of disputes. Each judicial opinion is not only important to resolving a particular legal dispute, but also to resolving similar disputes, or cases, in the future. Because of this, judges and lawyers within our legal system are continually researching an ever-expanding body of past opinions, or case law, for the ones most relevant to resolution of disputes.
To facilitate these searches West Publishing Company of St. Paul, Minn. (doing business as Thomson West) collects judicial opinions from courts across the United States, and makes them available electronically through its Westlaw™ legal research system. Users access the judicial opinions, for example, by submitting keyword queries for execution against a jurisdictional database of judicial opinions or case law. The Westlaw system also includes a ResultsPlus feature which suggest other content, particularly secondary legal content, such as legal encyclopedia articles, that are relevant to the specific case law queries. (See for example, US20050228788A1, which is incorporated herein by reference.)
At least one problem the present inventors recognized with this effective and highly successful system is that it does not fully appreciate the “one good case” methodology that many, if not most, legal researchers uses when conducting their research. This method generally entails a user running a relatively broad or intermediate query, manually identifying one highly relevant case law document from the search results, and then leveraging that good document to find other relevant documents.
Accordingly, the present inventors have recognized a need for improvement of information-retrieval systems for legal documents and potentially other document retrieval systems.